The Collaborative International Dictionary of English v.0.48:

Apepsy \A*pep"sy\, n. [NL. apepsia, fr. Gr. ?, fr. ? uncooked,
   undigested; 'a priv. + ? cooked, ? to cook, digest.] (Med.)
   Defective digestion, indigestion. --Coxe.
   [1913 Webster]